Palmitate induces fat accumulation by activating C/EBPβ-mediated G0S2 expression in HepG2 cells

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Hepatic lipid accumulation is a hallmark of metabolic dysfunction.
• Understanding the molecular mechanisms regulating fat deposition in the liver is crucial for developing therapeutic strategies.
• G0S2 (G0/G1 switch gene 2) has been implicated in lipid metabolism, but its specific role in palmitate-induced hepatic steatosis requires elucidation.

Purpose of the Study:

• To investigate the role of G0S2 in palmitate-induced hepatic lipid accumulation.
• To elucidate the transcriptional regulation of G0S2 by C/EBPβ (CCAAT/enhancer binding protein β) in response to palmitate.

Main Methods:

• HepG2 cells were treated with palmitate, C/EBPβ siRNA, or G0S2 siRNA.
• Gene expression (mRNA) of C/EBPβ, PPARγ, and target genes (G0S2, GPR81, GPR109A, Adipoq) was analyzed using qPCR.
• Protein expression of C/EBPβ, PPARγ, and G0S2 was assessed by Western blotting.
• Lipid accumulation was quantified using Oil Red O staining.
• Lipolysis was measured by glycerol release.

Main Results:

• Palmitate induced a dose-dependent increase in lipid accumulation and decrease in lipolysis in HepG2 cells.
• Palmitate upregulated the expression of C/EBPβ, PPARγ, G0S2, and other PPARγ target genes.
• Knockdown of C/EBPβ attenuated palmitate-induced lipid accumulation and enhanced lipolysis by reducing G0S2 expression.
• G0S2 knockdown also reduced lipid accumulation and enhanced lipolysis.

Conclusions:

• Palmitate induces hepatic lipid accumulation via the activation of C/EBPβ-mediated G0S2 expression.
• G0S2 plays a significant role in regulating hepatic lipid metabolism.
• Targeting the C/EBPβ/G0S2 pathway may offer a therapeutic approach for managing hepatic steatosis.